A. Field of the Invention
The present invention relates generally to an endoscopic technique or more particularly to a guide tube assembly which serves both as a guide tube for the endoscope and a suction tube for anesthesia.
B. Description of the Prior Art
An endoscope is an optical surgical instrument which utilizes flexible optical bundles and a flexible sheath for transmitting an image of an object caught at a forward end portion to an eyepiece assembly in a grip end. The endoscope is used for inspecting and treating a cancer and a polyp in a body cavity such as a bronchia and a stomach. When inserting the forward end portion and the flexible sheath into th body cavity for inspection and treatment, a guide tube is attached around the forward end portion and the flexible sheath so as to facilitate the insertion and prevent the wall of the body cavity from injury. In addition, the endoscope can be repeatedly inserted or pulled out by leaving the guide tube in a body cavity.
In an anesthetic operation, the endoscope is used for a manipulator of an anesthetic suction tube. For example, the suction tube is inserted into the bronchia with the aid of the endoscope and the anesthetic is introduced by way of the suction tube.
In the prior art, a silicon rubber tube is utilized for the guide tube of the endoscope. But, the cross section of the tube is easily deformed in the complicated body cavity and a friction resistance to the wall of the body cavity should not be disregarded, although the silicon tube is excellent in its flexibility. For the anesthetic suction tube, an integral molded tube made of PVC is widely used. But, the PVC tube is not so flexible, accordingly, the tube is difficult to be inserted into a desired position by the angle deflection mechanism of the endoscope. In addition, the PVC tube can not be sterilized in high-temperature after use. On the top of it, an anesthetic suction tube on which an olive oil is applied is used as guide tube means for both as the guide tube of the endoscope and the anesthetic suction tube. But, the guide tube means is difficult to be inserted into the desired position in the body cavity with the aid of the angle deflection means of the endoscope.